Treatment of glyceride oils and the resulting product



Patented Mar. 10, 1953 TREATMENT OF GLYCERIDE OILS AND THE RESULTING PRODUCT Karl F. Mattil, Chicago, Ill., assignor to Swift & Company, Chicago, 111., a corporation of Illinois No Drawing. Application July 24, 1950, Serial No. 175,660

14 Claims. (01. 260-3985) This invention relates to treating fatty glyceride material, and it has to do more particularly with the manufacture of an improved glyceride oil.

In the processing of glyceride fatty material an important problem is the removal of the high melting point glycerides which are normally solid at room temperatures and which tend to separate from the oil at relatively high temperatures. The conditioning of a glyceride fatty material to effectuate separation of the liquid fats from the undesirable solid fats must be carefully controlled in order to obtain the solid fat in a crystalline form suitable for filtration. Under the best conditions, filtration is inefficient, for the solid fats often separate as extremely small particles and remain suspended in the oil as colloidal dispersions, thus making the straining operation very difiicult.

I have now discovered that certain compositions hereinafter to be described and referred to as crystal inhibiting and modifying agents are extremely useful in prolonging the cold test of glyceride oils and in facilitating the Winterizing process.

In Winterizing a glyceride oil or processing a fatty material such as sperm oil or white grease to obtain lard oil, the conditioning of the oil or fatty material to effectuate separation of the liquid fats from the solid fats must be carefully controlled in order to obtain the solid fat in a crystalline form suitable for filtration. Under the best present-day conditions filtration is inefflcient, for the solid fats often separate as extremely small particles and remain suspended in the oil as colloidal dispersions, thus making the straining operation very difiicult. The difficulties attending the process of Winterizing as hitherto practiced may be overcome by incorporating into the glyceride oil or glyceride fatty material, such as sperm oil or white grease, a small amount of the crystal inhibitors and modifiers, hereinafter described. I have found that the addition of such substance profoundly affects crystallization whereby the crystals of the solid fats are rendered firmer and better defined. The form of the crystals is so improved that a more facile and. complete separation of the undesirable solids from the liquid constituents of the oil is effected. In addition to improving winterization, these substances are usually present in sufii- An important object of the present invention is, therefore, to provide an improved method for separating the solidified fat crystals from the liquid fats in glyceride fatty material.

Another object of the invention is to provide a method of improving the Winterizing of 'glyceride oils. I

Still another object of the invention is to'pro vide a glyceride oil having an improved cold test. A still further object of the present invention is to provide an improved glyceride oil which will remain clear and homogeneous for long periods of time at relatively low temperatures.

Another object of the invention is to provide" an improved glyceride oil which will exhibit good stability at relatively low temperatures when in- Broadly, the invention contemplates the addition to a glyceride fatty material, before or aft-' er winterization, of a small amount of a composition of the class of substances comprising alkyl-substituted aryl ether carboxylic acid salts. More particularly, the compounds or compositions contemplated by the present invention may be defined as sulphides of alkyl-substituted hydroxyaromatic compounds in which the hydroxyl hydrogen is replaced with an organic acid group which in turn has its carboxyl hydrogen substituted with its equivalent weight of a metal. Compounds of this general character include the sulphides of alkyl-substituted hydroxyaromatics (phenols) wherein the hydroxyl hydrogen is replaced with an aliphatic or aromatic metal carboxylate group. These compounds or compositions are all characterized by the presence of an aromatic nucleus in which at least one nuclear hydrogen has been substituted with a monoor poly-basic ether acid or an oxy-acid substituent having the hydrogen of at least one carboxyl group replaced with its equivalent weight of metal.

The preferred compounds or compositions constituted with an aliphatic hydrocarbon radical or group characteristic of an aliphatic hydrocarbon of high molecular weight which may be termed a heavy alkyl group. For obtaining the preferred group of compounds or compositions which possess the multifunctional .oil-improvmg properties in addition to being miscible with mineral oil, I have found that this heavy alkylf.

substituent in the sulphides of the aryl-ether acid salts under discussion must be derived from a predominantly straight chain aliphatic hydrocarbon of at least 20 carbon atoms such as characterize petroleum wax. As a matter of fact, paraffin wax is considered to be a preferred source of the heavy alkyl substituent, and it is for that 7 reason that the preferred compounds or compositions described herein are referred to as wax substituted. It is to be understood, however, that the term Wax as used herein is applied in a broad sense and is intended to include any pure compound or mixture of compounds predominantly aliphatic in nature and containing at least 20 carbon atoms which is susceptible of attachment to an aromatic nucleus to provide a substituent which, in the proper proportions, will impart to the characterizing group the multifunctional oil-improving properties referredto.

It will be understood that when a mixture of aliphatic hydrocarbon compounds such as characterize petroleum wax, for example, is used to provide the heavy alkyl substituent, the resulting composition will be an intimate mixture of sulphides of alkyl-substituted aryl ether acid salts which differ from each other with respect to the nature of the heavy alkyl substituent. In other words, where the alkylation of the aryl nucleus has been effected with a mixture of aliphatic hydrocarbons of at least 20 carbon atoms, the resulting composition will be a mixture of compounds differing in their heavy alkyl" substituents but having in common the characterizing nuclear group hereinabove referred to.

The compounds or compositions of the present invention may be further considered as composed of at least two of the above described alkyl-substituted hydroxyaromatic compounds interconnected by at least one atom of sulphur and may be characterized by the following general formulae:

in which n represents a whole number equal to at leastgl; and preferably from 1 to 4. The group O Z- COOM represents what I may term an etheracid salt group whereinZ represents an allphatic or aromatic radical and M representsthe hydrogen equivalent of a metal. This group (O-Z-COOM) may also be broadly defined as an ether carboxylic acid group in which the carboxyl hydrogenis substituted with its equivalent weight of metal. "The symbol R represents such groups as the following: hydrogen, alkyl, aralkyl', aryl,

4 alkaryl, hydroxyl, ester (organic or inorganic acyl groups), keto, alkoxy, alkyl sulphide, aryl sulphide, aroxy, ether alcohol, aldehyde thioaldehyde, :oxime, amido (organic or inorganic acyl groups), thioamido, carbamido, halogen, nitroso, amino, nitrosoamino, amidino, amino, N-thio, diazo, hydrazine, cyano, azoxy, azo and hydrazo; at least one B group being an oil-solubilizing alkyl group. In my preferred group of compounds or compositions at least one R represents an oil-solubilizing aliphatic radical or group containing at least 20 carbon atoms, and which is, as indicated above, to be hereinafter described as a wax group. In the preferred group of compounds or compositions wherein at least one B is a wax group, the remaining Rs represent residual hydrogen which may be replaced entirely or in part, with any of the groups of which R is broadly representative, and which may have a positive or negative or neutral oil-solubilizing eifect.

For purposes of definition and description' herein, the group O-Z-COOI-I, from which the above-described O-Z-CO OM group is derived, shall be designated as the ether carboxylic acid group and th term aryl ether carboxylic acid As aforesaid, Z may be an aromatic nucleus and in that event this aryl nucleus may have R substituents and, as contemplated herein, the condensation with the linkage (Sh may take place between the aryl nucleus or nuclei of such a Z group, and the foregoing general formulae are intended to include such modified derivatives,

Also when Z is aliphatic, it may contain R substituents excepting those of strictly aromatic origin, such as those resulting from diazotization, for instance.

In general, any metal may be employed as the letter M in compounds or condensation products of the aforesaid type to provide valuable oil addi tion agents. The metals contemplated herein may be broadly classified as metals of groups I to VIII, inclusive, of the periodic system. The selection of the metals will, of course, depend upon the use contemplated and include tin, calcium, barium, strontium, and cobalt. For the present purpose,however, magnesium and barium are particularly useful as the addition agents in glyceride oils.

It is important that the heavy alkyl substituent in the sulphide of the aryl ether carboxylio acid salts contain a heavy alkyl substituent in sufficient amount to render the compound or composition oil-miscible. The substituent must comprise a sufficient proportion of the composition as a whole so that when blended with glyceride oil it will remain in solution or colloidal suspension.

As indicated above, by the general formulaethe term sulphide as used hereinis inclusive; of the, monosulphides, disulphides, trisulphides, tetrasulphides, etc.

pounds referred to herein may be prepared in.

the manner described in U. S. Patent. No. 2,376,313, issued to Orland M. Reifi May 15, 1945.

The following examples illustrate the present It is also intended to inclu e. such polymers and related derivatives as may be;

gamer Example I To 100 grams of winterized cottonseed oil having a cold test of approximately hours there was added 0.1 per cent of magnesium carboxylate of paramn wax-substituted phenoxy acetic acid disulphide to form a uniform mixture therewith. After 90 hours in an ice bath under cold test condition the salad oil containing the said magnesium composition was entirely clear of crystal formation and'there was no cloudiness in the oil. After six days in the ice bath the oil showed crystal formation in the bottom thereof to a depth of 0.8 inch. The untreated cottonseed salad oil control sample contained 4.8 inches of crystals therein after six days in the ice bath. Moreover, with the foregoing disulphide, the yield of winterized cottonseed oil from cottonseed oil was increased from 67 per cent to 80 per cent by the addition of 0.05 er cent disulphide.

Example II To a sample of white grease was added 0.05 per cent of the barium carboxylate of parafiin wax-substituted phenoxy acetic acid disulphide and a uniformed mixture thereof formed. The sample was seeded for five days at about 55 F. After pressing to separate the liquid fraction from the solid glycerides it was found that the yield of oil therefrom was 62 per cent. The yield of oil from the control sample of white grease containing no added crystal modifying agent was 57 per cent.

Example III A sample of crude sperm oil containing 0.05 per cent stannous carboxylate of parafiin waxphenoxy stearic acid disulphide was seeded at 45 F. for six days and then pressed. The yield of sperm oil was '75 per cent while the yield of the control sample containing no added improving agent was 69 per cent.

As hereinbefore mentioned, the above described crystal inhibitors and modifiers may be .added to a glyceride fatty material before or after winterization. The addition of the crystal modifier before conditioning serves primarily to facilitate and improve the Winterizing operation. Although crystal formation is retarded in the presence of the additive, once the crystals are formed they are of such form as to settle quickly, and because of the nature of the crystals a sharp separation of the undesired solids from the liquid constituents of the oil is possible. An advantage of the improved filtering operation is that the yields of salad oil are greatly increased over the Winterizing process as hitherto practiced. Often it is desirable to add an additional small amount of the additive after the winterization operation so as to replace that which was filtered out along with the high-melting glyceride crystals.

It should be understood that the invention may be used in treating various fatty glyceride materials wherein a solid or crystalline fraction is separated from a liquid fraction, as in the separation of a crystalline fratcion from animal oils such as lard oil, oleo oil, greases, and sperm oil. In treating various vegetable and animal oils it i often desirable to separate a solid fraction such as stearin, palmitin, spermaceti and other highmelting point fractions by crystallizing such fraction with or without the presence of a solvent and then separating the crystallized fraction by cold settling, pressing, centrifuging or filtration.

The crystal modifying agents herein described may also be used to modify the crystal structure of the solid phase whereby it may be more readily separated from the liquid phase as when extracted with a suitable solvent.

Obviously many modifications and variations of the invention hereinbefore set forth may be made without departing from the spirit and scope thereof.

I claim:

1. An improved method of separating a glyceride fatty material into higher and lower melting point constituents, which comprises dispersing throughout a liquefied glyceride fatty material a small amount of a sulphide of a high molecular weight alkyl substituted aryl ether carboxylic acid salt, cooling the said fatty material to the lower melting point constituents, the crystals of said higher melting point constituents formed on cooling being firmer and better defined to facilitate separation from the said lower melting point constituents.

2. An improved method of separating a glyceride fatty material into higher and lower melting point constituents, which comprises dispersing throughout a liquefied glyceride fatty material a small amount of a sulphide of a high molecular weight alkyl substituted hydroxy aromatic compound in which the hydroxyl hydrogen is replaced with an organic acid group having the carboxylic hydrogen substituted with its equivalent weight of a metal, cooling the said fatty material to crystallize the higher melting point constituents, and then separating the said constituents from the lower melting point constituents, the crystals of said higher melting point constituents formed on cooling being firmer and better defined to facilitate separation from the said lower melting point constituents.

3. A method substantially as described in claim 2 wherein the organic acid group is an aliphatic organic acid group.

4. A method substantially as described in claim 2 wherein the organic acid group is an aromatic acid group.

5. A method substantially as described in claim 2 wherein the alkyl substituent of the hydroxy aromatic compound comprises a predominantly straight chain aliphatic hydrocarbon of at least 20 carbon atoms.

6. A method substantially as described in claim 5 wherein the straight chain aliphatic hydrocarbon comprises paraffin wax.

7. A method substantially as described in claim 6 wherein the said alkyl substituted hydroxy aromatic compound is selected from the group consisting of magnesium carboxylate of paraffin substituted phenoxy acetic acid disulphide, barium carboxylate of paraffin substituted phenoxy acetic acid disulphide, and stannous carboxylate of paraffin substituted phenoxy stearin acid disulphide.

8. A glyceride oil composition of improved cold test comprising a glyceride oil having incorporated therein a small amount of a sulfide of a high molecular weight alkyl substituted aryl ether carboxylic acid salt.

9. A glyceride oil composition of improved cold test comprising a glyceride oil having incorporated therein a small amount of a sulphide of a high molecular weight alkyl substituted hy-' droxy aromatic compound in which the hydroxyl hydrogen is replaced with an organic acid group having-:th'e carboxylinihy m fim s uhs tntedi i h' itsmuivalenmei h sf aim 110:1; composition sub'stantial s:asgd scn b dz claim. 9: where n; the ll-E1 v a t ir. lFQ i w phatic organic acidgrpup;

1:1,. Ahcomposition: substantiall as; described in claim 9;wherein the organicj'acid group s an r matic acid; group;

12. A composition substantially asdfiSGribed-in;

claim 9 wherein the alkyl substituent of th hydroxy: aromatic: compound, comprises a pr d minantly; straight chain-aliphatic; hydrocarbon. of

atleastzfl carbonatom 13-.v A: composition; substantially as described claim 12". wherein; the. straight; chain; aliphatic 15 9,

groug qonsisting, oi; mag esium. carhoxy iatefl 0L paraffin 's ubstitiited phenom acetic aLid' phide, barium carboxylalte of paraffin substitiitd phenoxy acetic acid disulphide, and stannous cetrboxylatev of:- pa-raffim substituted phenoxy stearin acid;disu1phide;..

REFERENCES CITED The following-references. are of record in the. file of this patent:

UNITED" STATES PATEN'IS- 

1. AN IMPROVED METHOD OF SEPARATING A GLYCERIDE FATTY MATERIAL INTO HIGHER AND LOWER MELTING POINT CONSTITUENTS, WHICH COMPRISES DISPERSING THROUGHOUT A LIQUEFIED GLYCERIDE FATTY MATERIAL A SMALL AMOUNT OF A SULPHIDE OF A HIGH MOLECULAR WEIGHT ALKYL SUBSTITUED ARYL ESTER CARBOXYLIC ACID SALT, COOLING THE SAID FATTY MATERIAL TO CRYSTALLIZE THE HIGHER MELTING POINT CONSTITUENTS, AND THEN SEPARATING THE SAID CONSTITUENTS FROM THE LOWER MELTING POINT CONSTITUENTS, THE CRYSTALS OF SAID HIGHER MELTING POINT CONSTITUENTS FORMED ON COOLING BEING FIRMER AND BETTER DEFINED TO FACILITATE SEPARATION FROM THE SAID LOWER MELTING POINT CONSTITUENTS. 